probe-state-before-acting

name	probe-state-before-acting
description	Cheap state probes before any action whose correctness depends on external state: creating a worktree or branch, pushing, rebasing, deleting files/code, running verification gates, coding against a third-party library, or triggering irreversible external steps (TestFlight upload, prod deploy). Every recorded incident in this repo's session history from this class was a skipped 5-second check: a worktree cut from main that missed the remote branch's existing work, gates run in the wrong repo root (invalidating a whole verification pass), and an App Store upload that hit the export-compliance wall on the user's device.
allowed-tools	["Bash","Read","Grep"]
metadata	{"author":"distilled-from-fable-5-sessions","version":"0.1.0-candidate"}

Probe State Before Acting

Act on what IS, not on what you remember or assume. Each probe below costs seconds; each recorded skip cost a user round-trip or a redone verification pass.

---

1. Before creating a worktree / starting on "a branch"

git fetch origin
git branch -a | grep <slug>          # does the branch already exist remotely?
git log --oneline -5 origin/<branch> # what's already on it?

Recorded miss: a worktree was created fresh-from-main for a named remote branch that already held 4 prototypes; the user had to point it out ("in this claude/landing-page-redesign-pn19ea already have some tho?" — ad88fbba L282, admission L289: "my fresh-from-main worktree missed it"). Also: name the branch explicitly at creation (<type>/<slug> per AGENTS.md) — the auto-worktree-* name had to be renamed at ship time in two recorded sessions.

2. Before running gates or claiming anything about "the repo"

git rev-parse --show-toplevel && git branch --show-current

Recorded miss: an entire verification pass ran in the main checkout instead of the worktree — "that invalidates the earlier analyze" (932ee514 L872, after wrong-root lint at L833). One line prevents the whole class.

3. Before pushing / after rebasing

git fetch && git log HEAD..origin/$(git branch --show-current) --oneline  # remote moved?

Recorded save: this exact probe caught an independently-merged fix mid-session, before push (ad88fbba L2379); after the ensuing rebase, state was re-verified ("quick sanity: cleanup state survived the rebase", L2408) and the conflict was resolved by keeping main's version — zero churn on freshly-merged code.

4. Before deleting code or files — map the blast radius

grep -rn "<module-or-symbol>" --include='*.ts*' .   # who imports/uses this?

then after the deletion, grep again for surviving consumers, and re-run the surviving surface live. Recorded standard: "Mapping the blast radius first so I don't cut a shared dependency" → shared leaf extracted before git rm → post-delete consumer grep → fresh build + live re-verify (ad88fbba L2279-2364).

5. Before coding against a third-party API — read the shipped artifact

ls node_modules/<pkg>/dist/*.d.ts    # then read the actual signatures

Never code against a remembered API. Recorded standard: r3f-globe's .d.ts read before the first line of globe code — "All API details verified (r3f-globe@1.6.0, default export, polygonsTransitionDuration...)" (ad88fbba L469→479). Same principle for builds: what a binary shipped with is what its Fastfile/--dart-define injected, not what the source suggests (42e3116a L43-47). For patterns/best practices, AGENTS.md already mandates Context7 — this skill covers the exact-signature check.

6. Before irreversible external actions — walk the one-way doors

Before a TestFlight upload, store submission, prod deploy, or any action you cannot undo: list the settings that only matter after the button is pressed, and check them first. Recorded miss: ITSAppUsesNonExemptEncryption was checked only after the upload; the user hit Apple's France export-compliance questionnaire on-device (f56af273 L663→L674). For TestFlight specifically: export compliance flag, signing identity, version/build number, and the release notes field.

---

Status: WEAKLY VALIDATED 2-0 (blind A/B on Opus, 2026-07-05) — read the caveat. Both wins were OFF-TRAP: the control arms also found the hidden branch and the string-path consumers, so the planted traps never differentiated; the blind verdicts rode on general implementation rigor instead. The skill measurably did not hurt and correlated with marginally better checks, but its core probes were not demonstrated to be load-bearing in this experiment. Transcript evidence remains the primary justification. Details: .claude/skills/_evidence/validation/results.md. Evidence: .claude/skills/_evidence/findings.md §F6 vs §D4/D5. Last verified: 2026-07-04. Drift re-check: grep -n 'Branch Naming' AGENTS.md && ls apps/mobile-flutter/ios/fastlane/Fastfile